The invention relates to a process for controlling a window with an electric window lifter for a motor vehicle, as known from German Patent Document DE 44 12 028 A1.
In the case of this known process for controlling a window pane with an electric window lifter drive for a motor vehicle, a so-called squeeze-in protection is implemented so that, when the window pane is closed, an obstacle causes a stopping of the motion of the window pane and possibly a moving-back of the window pane. As a result, no accidental squeezing-in will occur. In order to determine the position of the window pane in the case of this known process, the pulses of a d.c. driving motor moving the window pane are detected during the rotation of the motor, and the actual window pane position is determined on the basis of the counted pulses. When the window pane is lifted to the upper edge of the window or is lowered to the lower edge of the window, thus moves into its final stop position, the latter is detected by a microswitch, and the pulse counter is automatically set to 0 or to a previously defined value.
According to the present invention, when controlling window panes with a squeeze-in protection, on the one hand, it is ensured that the movement of the window pane is stopped in the event of an obstacle but that, on the other hand, in the event of a sluggishness of the pane, for example, in cold temperatures or when the pane seal is deformed, an obstacle is not erroneously detected and the movement of the window pane is stopped and/or vice-versa. In the case of sluggishness, the window pane should move over this sluggish point by means of a corresponding driving force. This driving force results in a hard movement of the window pane into its “pane closed” or “pane open” end positions.
In order to avoid that, preferably during the lowering, the window pane will not move unnecessarily hard against a final stop, a soft-stop position is defined. The movement of the window is stopped by the switching-off of the window lifter motor during the lowering of the window before the final stop has been reached, the so-called soft-stop position. The pane can thereby be stopped in a noiseless manner and the mechanical stress is reduced. Furthermore, by providing an overshoot logic, the advantage is achieved that the pane position can also be newly adapted in its end positions in order to, for example, be able to react to faulty transmissions of Hall pulses or a hardware and/or software fault. The overshoot logic can advantageously be generated by the driver himself by a repeated operating of the operating switch for the window pane.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.